Maybe it’s because we’ve been corrupted by BMW’s adoption of “Shock and Awe!” as its policy for redesigning cars, but when an automaker doesn’t go far enough with new models these days, it catches stick for laziness. General Motors’s new workhorse trucks, the Chevy Silverado and the GMC Sierra, aren’t radical reformations of the pickup genre—they’re not even radically different from the trucks they replace—and as a result, initial feedback has been harsh. It’s easy to do the automotive analogue of judging a book by its cover, assuming that if the sheetmetal is similar to the last-gen trucks, the underpinnings must be, too. And if they’re carrying over older mechanical components, it follows that they must be obsolete duds, right? Er, no. Not at all.

Going conservative with the Silverado and the Sierra redesigns was just as much a thoughtful determination as it would have been to style and engineer them for a Luc Besson acid-sci-fi flick. This isn’t to say that an evolutionary redesign will prove to be the right choice, necessarily, but just that it was the result of very serious, measured analysis at GM. Here were some of the company’s decision points, which we’ve picked up over the course of the past year in conversations with suited banker-type analysts and with General Motors executives.

GM wanted the Silverado and the Sierra to have universally appealing styling. You know the old marketing trope about whether a product will “play in Peoria?” For GM’s trucks, you can add Phoenix and Prattville, Alabama, along with Princeton, New Jersey and Plano, Texas. In short, everywhere. Lots of truck buyers don’t want radical change or crazy, punch-me-in-the-face styling. General Motors felt its cash-cow trucks needed clean, inoffensive styling that could sell anywhere.

We say: People probably don’t see the Ram and F-150 as over the top, but the GM trucks—new and old—look fine.

GM couldn’t risk compromising durability and affordability. Why don’t the new trucks use exotic metals, cut thousands of pounds, or adopt three-cylinder engines that run on bacon grease? Mark Reuss, GM’s VP, told us last year that, “If you look at profit and fuel economy on this, and you look at trying to lightweight a Silverado—if you look at what it takes to actually do this, and what it takes in cost of materials, and what it does on a real fuel-economy impact, you can’t get there. You want to make it really efficient, but you want to make it not too costly to get that efficiency. You risk duty-cycle issues as well.” The ad above, for a 2012 Silverado, really says it all.

We say: We didn’t expect carbon-fiber body panels, but a bigger effort in the powertrain department would have been nice. GM is calling the engine lineup all new, and we don’t have specs yet, but they’re the same displacement as the outgoing truck’s. People want to know they’re getting something modern. Ram’s V-6/eight-speed models are flying off the shelves.

The Mid-Size Colorado and Canyon will address efficiency-focused buyers. Reuss again: “We know that there’s a buyer for a really good Chevrolet lifestyle sport truck. The operating efficiency will go along with it. You’ve got 90 or 95 percent of the size, but you’ve got 120 percent of the efficiency because of the powertrains.” GM will go after the buyers whose primary concern is fuel economy with the mid-size Colorado and Canyon, which were designed from the outset to be smaller and lighter. Styling can be bolder, too. The pair will arrive in 2014.

We say: We’re excited for these new trucks, and like that they could be optimized for better fuel economy. But if they’re really 90 percent of the size of the Silverado and Sierra, the less-expensive (and presumably lower-profit-margin) Colorado and Canyon are just going to cannibalize sales from their big brothers.

This is a chance to better separate GMC and Chevy—and in so doing, make more money. Did you know that GMC is a money printer for General Motors? Versus Chevy and its customers, GMC buyers are more affluent and buy more options at higher prices. Considering that GMC needs no big investment, it’s probably the smartest example of rebadging in automotive history. The new Sierra and Silverado, we’ve been told, will be positioned and marketed differently, the GMC bundling options and features and trim levels in a better way to appeal to its customers—and to maximize profits.

We say: It’s very sound logic. We’ll need to wait for detailed pricing to come out for both brands’ trucks to make a judgment in this case, of course.